DNA Evidence
Name __________________________
1. What is DNA?
 DNA stands for ____________________ _________ and contains _____________ information.
 It is found on ___________________ located in the nucleus of our cells.
2. What makes up a DNA molecule?
 The sides or ____________________ of the DNA molecule are made up of ____________________
(deoxyribose) and ____________________ molecules.
 The rungs that form the middle of the molecule are made up of pairs of ____________________ or nitrogen
bases. ____________________ (A) pairs with ____________________ (T), while ____________________
(G) always pairs with ____________________ (C).
 The ____________________ of the bases determines the genetic ____________________.
 Label the diagram using the words listed below.
Backbone
Nitrogen Bonds
Adenine
Thymine
Cytosine
Guanine
3. How can DNA be used as evidence?
 Each person’s DNA is ____________________ from other people (except identical twins).
 DNA collected from a crime scene can either link a ____________________ to the evidence or
____________________ a suspect, similar to the use of fingerprints.
 DNA can identify a victim through DNA from ____________________, even when no body can be found.
 DNA can ____________________ crime scenes together by linking the same perpetrator to different scenes.
 DNA can place an ____________________ at a crime scene, in a home, or in a room where the suspect
claimed not to have been.
 DNA can _________________ a claim of self-defense and put a __________________ in the suspect's hand.
 It can change a story from an ____________________ to one of ____________________.
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4. What factors can affect DNA evidence?
Environmental factors (e.g., __________________, sunlight, __________________, __________________, and
mold) can affect DNA. Therefore, not all DNA evidence will result in a usable DNA profile. Further, DNA
testing cannot identify __________________ the suspect was at the crime scene or for _______ _____________.
5. What is CODIS?
CODIS stands for ____________________ ______________ _______________ _______________, which is an
electronic ____________________ of DNA profiles that can identify suspects.
6. DNA Matching
A. Who done it? _______
B. Whose your daddy? ______ C. Identical or not? _______
7. Which three statements below are true?
_____ 1. The DNA in a man's blood is the same as the DNA in his skin cells and saliva.
_____ 2. Each person's DNA is different from every other individual's.
_____ 3. DNA can be found in all the cells in our bodies except the blood cells.
_____ 4. DNA can have forensic value even if it is decades old.
_____ 5. DNA evidence was first used to get a conviction in a trial in 1987.
8. The Killer's Trail – Watch the video and then choose the best answer for each question.
1. Who was the victim?
A. Marilyn Sheppard
B. Sam Sheppard
2. What are the keys to DNA fingerprinting?
A.Chromosomes
B. Alleles
C. Sam Sheppard, Jr.
C. Nitrogen bases
3. Where did the scientist get the sample of DNA for Marilyn Sheppard?
A. Hair
B. Skin
C. Fingernail
4. Whose blood was found in the blood trail?
A. Marilyn Sheppard
B. Sam Sheppard
C. Neither
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